Particle Size Distribution of SBR and NBR Latexes by UV-VIS Turbidimetry near the Rayleigh Region

1996 ◽  
Vol 69 (4) ◽  
pp. 696-712 ◽  
Author(s):  
Mario A. Llosent ◽  
Luis M. Gugliotta ◽  
Gregorio R. Meira
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Average Diameter ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Data Treatment ◽  
Distribution Shape ◽  
Soft Polymer ◽  
Styrene Butadiene

Abstract This paper deals with data treatment problems that arise when turbidimetry is employed to estimate the particle size distribution (PSD) of soft polymer latexes with low diameter limits around 40 nm. Scanning electron microscopy and dynamic light scattering were used as comparison techniques. Industrial latexes of styrene-butadiene rubber (SBR) and of acrylonitrile-butadiene rubber (NBR) were investigated. The data treatment involved the use of Mie's Model to obtain an average diameter and/or the complete PSD. For estimating the complete PSD, a least squares optimization (with an imposed distribution shape) and a numerical deconvolution procedure (without assumptions on the distribution shape) were attempted. A synthetic example was solved to investigate the limits of the applied numerical methods. For the polymer refractive index functions, Cauchy's Law was used — and its adequate adjustment proved essential for good turbidimetric estimations. A reasonable agreement between the turbidity measurements and the other independent estimations was verified. For the SEM observations, the soft latexes were hardened by irradiation before observation, but negligible diameter variations were detected.

Particle Size, Structure and Powdering Process of Calcium Carbonate Nanoparticles Filled Powdered Styrene-Butadiene Rubber

2011 ◽  
Vol 415-417 ◽  
pp. 237-242
Author(s):  
Zhou Da Zhang ◽  
Xue Mei Chen ◽  
Guo Liang Qu
Keyword(s):  
Particle Size ◽  
Calcium Carbonate ◽  
Size Structure ◽  
Average Diameter ◽  
Rubber Matrix ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Particle Structure ◽  
Styrene Butadiene ◽  
New Particles

Calcium carbonate nanoparticles (nano-CaCO3) filled powdered styrene-butadiene rubber (P(SBR/CaCO3) was prepared by adding nano-CaCO3 particles, encapsulant and coagulant to styrene-butadiene rubber (SBR) latex by coacervation, and the particle size distribution, structure were studied. Scanning electron microscopy (SEM) was used to investigate the (P(SBR/CaCO3) particle structure, and a powdering model was proposed to describe the powdering process. The process includes: (i) the latex particles associated with the dispersed nano-CaCO3 particles (adsorption process) to form “new particles” and (ii) the formation of P(SBR/CaCO3) by coagulating “new particles”. The SEM results also shown that the nano-CaCO3 and rubber matrix have formed a macroscopic homogenization in the (P(SBR/CaCO3) particles and nano-CaCO3 dispersed uniformly in the rubber matrix with an average diameter of approximately 50 nm.

scholarly journals RESEARCH OF THE EJECTING PROPERTIES OF A POLYFRACTION BULK MATERIAL FLOW

2018 ◽  
Vol 3 (3) ◽  
pp. 46-51
Author(s):  
Евгений Попов ◽  
Evgeniy Popov
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Material Flow ◽  
Bulk Material ◽  
Aerodynamic Resistance ◽  
Average Diameter ◽  
Resistance Coefficient ◽  
Free Falling ◽  
The Given

This work is aimed at confirming the adequacy of the probabilistic and statistical approach to determining the aerodynamic resistance coefficient of particles in a flow of the free falling polyfractional material, suggested by the author. The aerodynamic resistance coefficient of particles in a flow of falling material is defined by calculating the probability of finding particles out of air shadows of the neighboring particles. The laboratory experiment was performed on the offered experimental samples of bulk materials having different particle size distribution, but the identical average diameter of particles. The design of a laboratory experimental installation which allows determining the consumption of air, ejected by a polyfractional material flow, was described. The amount of the air, ejected with experimental samples, depends on their particle size distribution that confirms the insufficiency of describing the properties of bulk material only with the average diameter value. The given comparison of results of the analytical calculations with experimental data shows the reliability and adequacy of the calculated values.

scholarly journals Characterizing Distributions of Tensile Strength and Crack Precursor Size to Evaluate Filler Dispersion Effects and Reliability of Rubber

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 203 ◽  
Author(s):  
Christopher G. Robertson ◽  
Lewis B. Tunnicliffe ◽  
Lawrence Maciag ◽  
Mark A. Bauman ◽  
Kurt Miller ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Average Diameter ◽  
Strength Distribution ◽  
Glass Beads ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Failure Distribution ◽  
Filler Dispersion ◽  
Control Compound ◽  
Styrene Butadiene

Undispersed filler agglomerates or other substantial inclusions/contaminants in rubber can act as large crack precursors that reduce the strength and fatigue lifetime of the material. To demonstrate this, we use tensile strength (stress at break, σb) data from 50 specimens to characterize the failure distribution behavior of carbon black (CB) reinforced styrene-butadiene rubber (SBR) compounds. Poor mixing was simulated by adding a portion of the CB late in the mixing process, and glass beads (microspheres) with 517 μm average diameter were introduced during milling to reproduce the effects of large inclusions. The σb distribution was well described with a simple unimodal Weibull distribution for the control compound, but the tensile strengths of the poor CB dispersion material and the compounds with the glass beads required bimodal Weibull distributions. For the material with the lowest level of glass beads—corresponding to less than one microsphere per test specimen—the bimodal failure distribution spanned a very large range of σb from 13.7 to 22.7 MPa in contrast to the relatively narrow σb distribution for the control from 18.4 to 23.8 MPa. Crack precursor size (c0) distributions were also inferred from the data, and the glass beads introduced c0 values in the 400 μm range compared to about 180 μm for the control. In contrast to σb, critical tearing energy (tear strength) was unaffected by the presence of the CB agglomerates and glass beads, because the strain energy focuses on the pre-cut macroscopic crack in the sample during tear testing rather than on the microscopic crack precursors within the rubber. The glass beads were not detected by conventional filler dispersion measurements using interferometric microscopy, indicating that tensile strength distribution characterization is an important complementary approach for identifying the presence of minor amounts of large inclusions in rubber.

News from the M in CMP - Viscosity of CMP Slurries, a Constant?

2003 ◽  
Vol 767 ◽  
Author(s):  
W. Lortz ◽  
F. Menzel ◽  
R. Brandes ◽  
F. Klaessig ◽  
T. Knothe ◽  
...  
Keyword(s):  
Particle Size ◽  
Shear Rate ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
High Shear Rate ◽  
Bet Surface Area ◽  
Energy Concentration ◽  
High Shear ◽  
Polishing Pad ◽  
Distribution Shape

AbstractIt is well known and accepted that the viscosity of CMP-slurries has an effect on polishing results. Even though the literature on rheology recognizes that viscosity is not always constant and the slurry can show non-Newtonian behavior or even dilatant effects, all calculations have been performed with constant viscosity.However, the “real” viscosity of a CMP-slurry during polishing can change significantly with shear rate.The typical equipment for viscosity measurement is based on a rotating cylinder or a plate. But even with a plate system it is only possible to reach a shear rate range up to 50,000 1/sec. A calculation of the shear rate between the wafer and the polishing pad is based on a relative velocity of 1 m/sec and a distance between the wafer and the pad of 20 μm; this correlates to a shear rate of 50,000 1/sec. If parts of the polishing pad come closer to the wafer or especially closer to the edge of structures on the wafer (for example 1 μm), the shear rate will increase locally to 1,000,000 1/sec.When the shear rate is high enough, viscosity depends mostly on hydrodynamic factors like viscosity of continuos phase, solids content, particle size, particle size distribution and shape of the particles.The shape of fumed metal oxides is controlled during the synthesis in the flame process. But the slurry-making process is also responsible for particle size distribution, shape of the particle and the high shear rate viscosity of the CMP-slurry.The high shear rate viscosity of different silica slurries in dependence from BET-surface area, used milling energy, concentration and preparation direction was measured in this investigation.

Co-milled silica and coppiced wood biochars improve elongation and toughness in styrene-butadiene elastomeric composites while replacing carbon black

2018 ◽  
Vol 50 (8) ◽  
pp. 667-676 ◽  
Author(s):  
Steven C Peterson ◽  
Nirmal Joshee
Keyword(s):  
Particle Size ◽  
Carbon Black ◽  
Populus Tremuloides ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Tire Industry ◽  
The Us ◽  
Styrene Butadiene ◽  
Elastomeric Composites ◽  
Lower Carbon

Carbon black (CB) is a petroleum by-product with a million ton market in the US tire industry. Finding renewable substitutes for CB reduces dependence on oil and alleviates global warming. Biochar is a renewable source of carbon that has been studied previously as a replacement for CB in styrene-butadiene rubber (SBR) composites. However, biochar typically has lower carbon content, higher ash content, and larger particle size, which are all significant detractors to making biochar a viable drop-replacement for CB. In this study, high carbon and low ash biochars made from fast-growing Paulownia elongata and Populus tremuloides were co-milled with small amounts of silica in order to reduce the particle size, and the biochar/silica blends were then used to partially replace CB in SBR composites. Using this method both Paulownia and poplar biochars were able to replace 30% of the CB filler and improve elongation and toughness with virtually no loss of tensile strength, compared to the 100% CB-filled control composite.

Fabrication of Sulfonated Bamboo Charcoal-Chitosan (sBC-CS) Hybrid and its Applications for Reinforcement of Styrene-Butadiene Rubber

2017 ◽  
Vol 872 ◽  
pp. 160-164
Author(s):  
Xiang Xu Li ◽  
Ur Ryong Cho
Keyword(s):  
Particle Size ◽  
Tensile Strength ◽  
Filling Ratio ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Bamboo Charcoal ◽  
Rubber Composites ◽  
Vulcanized Rubber ◽  
Styrene Butadiene ◽  
Latex Compounding

Styrene-Butadiene Rubber (SBR) composites incorporated with different fillers with similar filling ratio, were fabricated by latex compounding method. The particle size, tensile strength, abrasion resistance of the vulcanized rubber composites were investigated. The sulfonated bamboo charcoal-chitosan hybrid (sBC-CS) showed great dispersion rate and smaller particle size compared with those of other fillers. In addition, this composite exhibited the best mechanical reinforcing performance among the four fillers.

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